Pop bumpers are well known in electrically operated pinball machines. Such pop bumpers are generally distributed throughout the play field across which the ball rolls. When a pinball strikes a pop bumper, a switch is depressed which typically causes a score to be recorded. Also, typically, an angled ring is depressed by a solenoid against the ball, to forcefully impel or thrust the ball away from the bumper, for further play of the ball. The pop bumper is popular in electrically operated pinball machines because they can add added life and action to the ball, by providing it with added rolling energy.
In the presently available pop bumpers, a ball skirt or flange serves as a switch, being positioned to be depressed by the ball when the ball rolls against the pop bumper. Such ball skirts are typically circular plates with a downwardly facing concave side and an upwardly facing convex side. A generally vertical rod is welded or otherwise attached to the lower face of the ball skirt or flange, and projects downwardly into engagement with a dish carried on an arm, in which the dish carries an upwardly facing concave surface. Thus, as the skirt or flange is depressed from any side by a ball, the vertical rod is rotated outwardly. In so doing, it engages a peripheral portion of the dish on the arm, to force the dish and arm downwardly. This is typically accomplished because the radius of curvature of the concave dish is less than the radius of the arc in which the lower tip of the rod rotates.
The arm that carries the dish may be connected to a switch, so that when the dish is depressed by the rod rotating out of vertical alignment by depression of one edge of the ball skirt, the switch may be actuated to cause a score to be recorded, and to cause the means for thrusting the ball away from the pop bumper to be actuated.
Then, when the ball skirt or flange is no longer depressed by the ball, it rotates back to its normal position, taking the rod with it, which permits the dish and arm to be raised again to shut the switch off.
As a problem which has arisen with this design of pop bumper, it has been found that the vertical rod sometimes "hangs up" or becomes stuck in its engagement with a peripheral portion of the dish. Thus, the switch arm remains permanently depressed, and the switch in a permanently "on" position. Often because of this, the circuitry controlled by the switch burns out before the problem can be repaired.
In the past, the Bally Company attempted to solve this problem making use of a vertical rod positioned against a ball skirt or flange in which the vertical rod moved only upwardly and downwardly and not from side-to-side. The project was apparently unsuccessful because manufacturing of that structure was terminated rather quickly. It is believed that on problem that arose with respect to such a structure is that when a ball strikes the ball skirt or flange to depress it, the distance that the vertical rod is pressed downwardly is quite small. Sometimes, that distance was inadequate to reliably actuate the switch which was supposed to be in engagement with and controlled by movements of the rod.
In accordance with this invention, means are provided for causing movements of a vertical actuating rod to be magnified, so that such movements will cause a switch with which it interacts to be moved to a greater degree than the movements of the vertical rod. Thus, small movements of the vertical rod can nevertheless result in larger movements of the actuating arm of the switch, for example, resulting in reliable actuation of the switch when a ball rolls against the ball skirt or flange.
Further in accordance with this invention, an improved pop bumper is provided which is less likely to become stuck in the "on" position in the manner of the prior art. Nevertheless, the pop bumper functions in a manner which has the advantages of prior art pop bumpers while avoiding this problem, and while also being manufactured of more conventional parts which may be less expensive, for manufacturing cost advantages when compared with those of the prior art.